In order to overcome the perinatal lethality of GDF11 deletion in mice, we have made a pancreas specific deletion of the mouse GDF11 gene using the Cre-loxP method. We have begun to characterize the phenotype by measuring body weight during postnatal growth and body composition in both sexes. We have also analyzed glucose metabolism in adult mice of different ages and on high fat diets. We have determined gene expression differences in islets from wild type and mutant mice at several ages and both sexes and are analyzing the cell subtype proportions.